Continuous positive airway pressure (CPAP) systems typically use flexible plastic tubing or hose, for example of polyethylene or polypropylene, for conveying gases such as air or oxygen to a patient.
U.S. Pat. No. 7,472,707 (Wood et al.) includes a disclosure of a ribbed air delivery hose, with a round or oval profile, designed so that the hose's cross-sectional area does not change when the hose is bent (e.g. around a patient's ear).
Regardless, it remains an issue that a CPAP mask or cannula (e.g. an apnea cannula fitted in a nare or nares) can be pulled into undesirable positions by movement of the patient resulting in loss of the seal or removal or partial removal of the mask/cannula. If there is a loss of the seal, the CPAP system may sense a loss of air/oxygen delivery and respond by increasing flow, which is inefficient and may be noisy. Condensation in the tubing/hose is another common issue. The desire to mitigate pulling on a nasal continuous positive airway pressure (NCPAP) breathing interface device (e.g. mask or cannula) is particularly important in the case of such a device that does not include a retention strap, which may be uncomfortable and inconvenient to adjust.
In this regard, US 2009/078259 (Koolj et al.) discloses a breathing tube that is extensible and retractable via a configuration similar to a flexible drinking straw to accommodate movement of the patient, for example movement of the patient's head. The extensible/retractable tube may be attached to a patient interface using a swivel elbow assembly. The retractable tube may be of sufficient length to accommodate some movement of the patient's head without extension or retraction of the tube.